I bought a couple of these from aliexpress fully assembled[0] (along with some massive terrifying batteries[1]). They're cool little devices. You can send messages via the app on your phone or by plugging them into your computer via USB. There's evidently also some wifi connectivity that I haven't experimented with at all.

Message shows up in the chat room on the phone and on the other devices linked to the room. Planning to play with them for camping Soon™.

[0]: < https://www.aliexpress.com/item/2255800992363816.html?spm=a2...> [1]: <https://www.18650batterystore.com/products/sanyo-ncr18650ga>